1. Field of the Invention
The invention relates to a liquid crystal display apparatus and a production method thereof.
2. Description of Related Art
A liquid crystal display apparatus is a display device that applies a voltage to a liquid crystal layer sandwiched between a pair of substrates to change orientation of liquid crystal molecules, and displays black-and-white or color characters or images by utilizing the change of light transmission characteristics of the liquid crystal layer resulting from the change of the molecular orientation.
FIG. 40 is a schematic sectional view showing a simplified construction of a black-and-white liquid crystal display apparatus 5 according to the prior art.
The liquid crystal display apparatus 5 includes an opposing substrate 51, a transparent substrate 60 and a liquid crystal layer 57 that is formed by injecting a liquid crystal between the opposing substrate 51 and the transparent substrate 60. A shading film 59, a thin film electrode 58 and an orientation film 55a are formed on the transparent substrate 60. Signal wiring 52, driving devices 53 such as thin film transistors (abbreviated as “TFT”), pixel electrodes 54 and an orientation film 55b are formed on the opposing substrate 51. A spacer 56 formed of glass or plastic is sandwiched between the opposing substrate 51 and the transparent substrate 60 to secure a predetermine gap between the opposing substrate 51 and the transparent substrate 60. The spacer 56 is sprayed onto either one of the opposing substrate 51 and the transparent substrate 60. Alternatively, the spacer 56 is formed on either one of the opposing substrate 51 and the transparent substrate 60 by photolithography (refer to “The Latest Liquid Crystal Application Technologies”, edited by Liquid Crystal Application Technology Research Society, published by K.K. Kogyo Chosakai, Dec. 15, 1994, p 3–6).
As shown in FIG. 40, the signal wiring 52, the driving device 53 and the shading film 59 are formed in a non-display portion 70 not used for display in the liquid crystal display apparatus 5 in such a fashion as to protrude towards the liquid crystal layer 57. Therefore, a gap h1 defined by the orientation films 55 opposing each other in the non-display portion 70 is remarkably small and is smaller than a gap h2 defined by the orientation films 55 opposing each other in a display portion 71 used for display (h1<h2). Therefore, the signal wiring 52, the driving device 53 and the shading film 59 operate as a barrier in the non-display portion 70 when the liquid crystal is injected between the opposing substrate 51 and the transparent substrate 60 during the fabrication process of the liquid crystal display apparatus 5. Because this barrier impedes fluidization of the liquid crystal and makes a fluidization path of the liquid crystal smaller, the liquid crystal cannot be injected smoothly and an injection speed of the liquid crystal drops, so that a long time is necessary to inject the liquid crystal.
As the thickness of the liquid crystal display apparatus has become smaller and smaller in recent years, the gap between the opposing substrate 51 and the transparent substrate 60 has become smaller, and the gap h1 of the non-display portion 70 described above has become smaller, too. Consequently, the fluidization path of the liquid crystal in the non-display portion 70 has become smaller and the injection speed drops, thereby rendering a serious problem that the injection time remarkably increases.
As the liquid crystal display apparatus has become greater in size, the number of pixels has become greater, and the adverse influences of the small gap h1 of the non-display portion 70 have become greater. In some cases, it has become difficult to inject the liquid crystal into the liquid crystal display apparatus as a whole.